Comparative study of various supermarket refrigerating systems in European climate context

Abstract

Due to the enormous carbon footprint of food retail stores the interest in natural working fluids, such as propane (R290) and CO2 (R744), has recently intensified in the commercial refrigeration sector. In this theoretical investigation the performance of various technologies employing low-global warming potential (GWP) refrigerants was compared in an average-size supermarket located in different European cities. It was found that a R744 multi-ejector enhanced parallel compression system consumed from 24.6% in Athens (Greece) to 37.1% in Oslo (Norway) less electricity compared to a R404A direct expansion refrigerating solution (baseline). Also, the results obtained suggested that CO2/R1234ze(E) indirect arrangements perform slightly better than CO2/R290 indirect units. In particular, the former offered, at best, energy savings by 6.9% (in Athens) over the selected baseline. Finally, it was revealed that the solution outfitted with the multi-ejector block features between 36.8% and 50.3% in heating mode and between 3.1% and 18% in air conditioning (AC) mode lower total power input than separated hydrofluorocarbon (HFC) units over the selected range of outdoor temperatures. It could be concluded that highly efficient as well as climate friendly technologies are readily available for the European food retail industry.